Thermoacoustic module, thermoacoustic device, and method for making the same

Abstract

A thermoacoustic module includes a substrate, at least one first electrode and at least one second electrode located on the substrate, a cover board spaced from the substrate, and a sound wave generator. The cover board defines a plurality of openings. The sound wave generator is located between the cover board and the substrate. The sound wave generator is electrically connected to the at least one first electrode and the at least one second electrode. The sound wave generator is capable of causing a thermoacoustic effect.

What is claimed is: 
     
       1. A thermoacoustic module comprising:
 a substrate; at least one first electrode and at least one second electrode located on the substrate; a cover board defining a plurality of openings and being spaced from the substrate; and a sound wave generator at least partly suspended between the cover board and the substrate, and the sound wave generator is electrically connected to the at least one first electrode and the at least one second electrode; wherein the sound wave generator is capable of causing a thermoacoustic effect; wherein the sound wave generator is capable of generating sound by converting electrical signals into heat, direct heating medium surrounding the sound wave generator, and causing thermal expansions and thermal contractions of the medium surrounding the sound wave generator. 
 
     
     
       2. The thermoacoustic module of  claim 1 , wherein the sound wave generator comprises at least one carbon nanotube film, the at least one carbon nanotube film comprises a plurality of successive carbon nanotubes joined end-to-end by van der Waals attractive force therebetween, the plurality of successive carbon nanotubes in the at least one carbon nanotube film are substantially aligned along a single direction and substantially parallel to a surface of the at least one carbon nanotube film. 
     
     
       3. The thermoacoustic module of  claim 2 , wherein the single direction extends from the at least one first electrode to the at least one second electrode. 
     
     
       4. The thermoacoustic module of  claim 1 , wherein the substrate and the cover board are comprised of a material selected from the group consisting of plastics, ceramics, diamond, quartz, glass, resins, wood and combinations thereof. 
     
     
       5. The thermoacoustic module of  claim 1 , wherein the cover board is a braiding or network weaved of metal, plastic, or resin wires. 
     
     
       6. The thermoacoustic module of  claim 1 , wherein the cover board is a planar metal mesh, the plurality of openings are uniformly distributed. 
     
     
       7. The thermoacoustic module of  claim 1 , wherein the at least one first electrode comprises a plurality of first electrodes, the at least one second electrode comprises a plurality of second electrodes, and the plurality of first electrodes and the plurality of second electrodes are located on the substrate in a staggered manner 
     
     
       8. The thermoacoustic module of  claim 1  further comprising at least two supporters located between the cover board and the substrate, wherein the at least two supporters separate the cover board from the substrate. 
     
     
       9. The thermoacoustic module of  claim 8 , wherein a height of the at least two supporters is greater than a sum of a height of the first electrode or the second electrode and a thickness of the sound wave generator. 
     
     
       10. The thermoacoustic module of  claim 1  further comprising at least one first spacer located between the substrate and the sound wave generator, and the at least one first spacer provides some support to the sound wave generator. 
     
     
       11. The thermoacoustic module of  claim 10 , wherein the at least one first spacer is located on the substrate between the at least one first electrode and the at least one second electrode. 
     
     
       12. The thermoacoustic module of  claim 1 , wherein the cover board is spaced from the sound wave generator. 
     
     
       13. The thermoacoustic module of  claim 12  further comprises at least one second spacer arranged on the cover board, and the at least one second spacer provides support for the sound wave generator. 
     
     
       14. The thermoacoustic module of  claim 13 , wherein the sound wave generator is sandwiched by the at least one second spacer and the at least one first and second electrodes. 
     
     
       15. A thermoacoustic device comprising:
 a thermoacoustic module comprising: a substrate; at least one first electrode and at least one second electrode located on the substrate; a cover board, spaced from the substrate, having a mesh structure defining a plurality of openings; and a sound wave generator located between the cover board and the substrate, and the sound wave generator is electrically connected to the at least one first electrode and the at least one second electrode; and a frame securing the thermoacoustic module; wherein the sound wave generator is capable of causing a thermoacoustic effect; wherein the sound wave generator is capable of generating sound by converting electrical signals into heat, direct heating medium surrounding the sound wave generator, and causing thermal expansions and thermal contractions of the medium surrounding the sound wave generator. 
 
     
     
       16. The thermoacoustic device of  claim 15 , wherein the frame comprises two fixing frames engaged with each other, and the thermoacoustic module is secured between the two fixing frames. 
     
     
       17. The thermoacoustic device of  claim 16 , wherein one of the two fixing frames comprises four frame members joined end to end to define an opening to accommodate and hold the thermoacoustic module. 
     
     
       18. The thermoacoustic device of  claim 17 , wherein two of the four frame members each define a heat dissipating groove. 
     
     
       19. The thermoacoustic device of  claim 15 , wherein the sound wave generator comprises at least one carbon nanotube film, the at least one first electrode and the at least one second electrode are electrically connected to the at least one carbon nanotube film, and the at least one carbon nanotube film comprises a plurality of carbon nanotubes, joined end-to-end by van der Waals attractive force therebetween, aligned along a single direction and substantially parallel to a surface of the at least one carbon nanotube film. 
     
     
       20. The thermoacoustic device of  claim 19 , wherein the single direction extends from the at least one first electrode to the at least one second electrode.